Evaluation of Diffusion Coefficient of Oxygen in Liquid Silver from AC Impedanceof an Electrochemical Cell based on Solid Electrolyte and Molten Silver Electrode

Abstract

The diffusion coefficient of oxygen in liquid silver was evaluated by analyzing the relaxation process of the electrode reaction of an AC-polarized solid galvanic cell employing stabilized zirconia as the solid electrolyte and liquid silver as the electrode. The AC impedance of the cell was measured for various amounts of oxygen at the silver electrode in the frequency range from 1 mHz to 1000 mHz at temperatures of 1273–1373 K . The well-defined Warburg impedance, which was expected when the overall electrode reaction rate was controlled by the diffusion of oxygen in liquid silver, was obtained for a certain limited condition. The diffusion coefficients determined from this impedance agreed fairly well with those reported by other authors. The factors causing errors in the evaluation of the diffusion coefficient were examined.